Dodecahedron CsPbBr<sub>3</sub> Perovskite Nanocrystals Enable Facile Harvesting of Hot Electrons and Holes
Ayendrila Das, Debopam Acharjee, Mrinal Kanti Panda, Asit Baran Mahato, Subhadip Ghosh
Abstract
This Letter reports the facile harvesting of hot carriers (HCs) in a composite of 12-faceted dodecahedron CsPbBr 3 nanocrystal (NC) and a scavenger molecule. We recorded ∼3.3 × 10 11 s –1 HC cooling rate in NC when excited with ∼1.4 times the band gap energy ( E g ), increasing to >3 × 10 12 s –1 in the presence of scavengers at high concentration due to the HC extractions. Since the observed intrinsic charge transfer rate (∼1.7 × 10 12 s –1 ) in our NC–scavenger complex is about an order of magnitude higher than the HC cooling rate (∼3.3 × 10 11 s –1 ), carriers are harvested before their cooling. Further, a fluorescence correlation spectroscopy study reveals NC tends to form a quasi-stable complex with a scavenger molecule, ensuring charge transfer completed (τ ct ≈ 0.6 ps) much before the complex breaks apart (>600 μs). The overall results of our study highlight the promise shown by 12-faceted NCs and their implications in modern applications, including hot carrier solar cells.